title: Ultrafast x-ray photoelectron spectroscopy in the microsecond time domain.
abstract: We introduce a new approach for ultrafast in situ high-resolution X-ray photoelectron spectroscopy (XPS) to study surface processes and reaction kinetics on the microsecond timescale. The main idea is to follow the intensity at a fixed binding energy using a commercial 7 channeltron electron analyzer with a modified signal processing setup. This concept allows for flexible switching between measuring conventional XP spectra and ultrafast XPS. The experimental modifications are described in detail. As an example, we present measurements for the adsorption and desorption of CO on Pt(111), performed at the synchrotron radiation facility BESSY II, with a time resolution of 500 μs. Due to the ultrafast measurements, we are able to follow adsorption and desorption in situ at pressures of 2 × 10(-6) mbar and temperatures up to 500 K. The data are consistently analyzed using a simple model in line with data obtained with conventional fast XPS at temperatures below 460 K. Technically, our new approach allows measurement on even shorter timescales, down to 20 μs.
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Höfert
authors.forename: C
authors.initials: C
authors.lastname: Gleichweit
authors.forename: H-P
authors.initials: HP
authors.lastname: Steinrück
authors.forename: C
authors.initials: C
authors.lastname: Papp